In long known practices for supplying hot water, a casing has a first compartment which houses a tank fed with cold tap water and the casing includes a second compartment housing both a heater of fossil fuel burning type and a water conduit. The conduit is in fluid-flow communication with the water tank for receiving water to be heated and also with casing outlet piping serving a consumer. In present day apparatus, the heater is typically a fuel-fired burner and the water conduit is coiled upwardly in spiral configuration in the path of issuance of the burner flame and therebeyond toward the heater exhaust funnel or stack.
Various disadvantages attend this commonly known non-portable and bulky apparatus with its customized heater and coil compartment, particularly where one seeks a portable, relatively small and inexpensive hot water supply unit for use such as is made in local auto repair shops, e.g., in the degreasing of engines prior to tune-up and other repair activities. In that field of endeavor, degreasing of engines is desirable from the points of view of facilitating the work of the mechanic and extending the lifetimes of hoses and other engine parts contaminated by grease buildup.
The conflicting industrial demands of, on the one hand, having a light-weight, portable and inexpensive apparatus and, on the other hand, having apparatus with the capability of furnishing promptly a continuous supply of degreasing fluid have not been accomodated, in applicant's view, in heretofore known apparatus.